Integrated circuits, in particular those equipped with memories containing sensitive information, have to be protected to the greatest possible extent against attacks, in particular attacks intended to discover data stored in memory cells of the integrated circuit.
A potential attack may be carried out using a focused ion beam (well known under the acronym FIB by those skilled in the art), for example by way of a laser beam.
The effectiveness of such an attack increases when the substrate of the integrated circuit is thinned by the attacker, from its rear face, so as to get as close as possible to the components of the integrated circuit that are formed at the front face of the integrated circuit.
There are means for detecting thinning of the substrate that make it possible to protect integrated circuits against this type of attack.